最新刊期
- “最新研究揭示，金属卤化物钙钛矿发光二极管（PeLEDs）在照明和显示领域具有巨大潜力。伦敦大学团队发现，仅需3分钟红光照射，即可显著改善视力下降。通过结构优化，结合微腔结构，PeLEDs的外量子效率（EQE）实现成倍增长，最大EQE可达11.26%，为护眼红光PeLEDs的实现提供了有力保障。”摘要：Metal halide perovskite light-emitting diodes （PeLEDs） have wide color gamut and high color purity， with broad application prospects in lighting and displays. A groundbreaking study by a research team at the University of London published in Scientific Reports found that exposure to red light for just 3 minutes a day can significantly alleviate vision decline. The tunability of perovskite's spectrum and its high color purity provide assurance for the realization of eye-protective red-emitted PeLEDs. Unlike previous interface engineering or ligand engineering methods， this paper proposes a new approach to enhance the external quantum efficiency （EQE） of quasi-two-dimensional perovskite red PeLEDs by combining them with microcavity structures to achieve narrower linewidths in electroluminescent devices. The results show that by integrating distributed Bragg reflectors （DBRs） with PeLEDs， narrow linewidth high-performance PeLEDs based on microcavity structures were designed and fabricated， achieving a doubling of EQE on top of narrowing the electroluminescence （EL） full width at half maximum for microcavity PeLEDs， with a maximum EQE reaching 11.26%. Compared to reference devices prepared under the same conditions， PeLED devices with microcavity structures narrowed their EL linewidth to one-third that of reference devices， only 11 nm.关键词：quasi-two-dimensional perovskite;distributed bragg mirror;red emitted;electroluminescence;half-height full width
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更新时间：2024-07-15 -
Research on microfluidic photodynamic therapy based on singlet oxygen fluorescence sensing 增强出版 AI导读
“最新研究进展显示，微流控生物芯片和荧光纳米传感器在模拟肿瘤微环境下的光动力疗法中发挥关键作用，为提高临床疗效提供了新思路。”摘要：Photodynamic therapy （PDT）， as a new type of phototherapy technology， has the advantages of non-invasive and low toxic side effects， and has important application prospects in clinical medicine. Currently， PDT research is mainly based on statically cultured tumor cells， which significantly differ from the actual tumor microenvironment and often lead to poor clinical efficacy of PDT. This paper designs and develops a microfluidic biochip for tumor PDT， and prepares a fluorescent nanosensor （λex = 410 nm； λem = 460 nm） to fluorescently sense the production of singlet oxygen during the PDT process， analyzing the main factors affecting the inactivation of tumor cells by PDT. The results show that reducing the pH of the culture medium from 7.4 to 6.8 （environmental acidification） and increasing the injection flow rate from 5 μL/h to 20 μL/h （increased shear stress） both reduce the phagocytic efficiency of tumor cells towards nano photosensitizers. In the early stage of PDT， the oxygen content is sufficient （<30 s）， and the differences in photosensitizer dosage， microacidification， and mechanical microenvironment have little effect on the yield of singlet oxygen. The cell phototoxicity is similar. In the late stage of PDT （30-180 s）， the oxygen content decreases， the yield of singlet oxygen decreases， and different tumor microenvironment parameters result in different cellular phototoxicity. This work explores the production of singlet oxygen during PDT in a simulated tumor microenvironment through fluorescence sensing， providing useful references for promoting the clinical development of tumor PDT.关键词：fluorescence sensing;singlet oxygen;microfluidic chip;photodynamic therapy- 35
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更新时间：2024-07-15 - “在有机发光二极管（OLED）领域，研究人员成功合成了两种新型高效红光铱（III）配合物，展现出优异的光物理特性和器件性能，为OLED的高性能化提供了新方案。”摘要：At room temperature， two efficient red iridium（III） complexes， （4tfmpq）2Ir（Pydtc） and （4tfmpq）2Ir（Indtc）， containing a unique four-membered ring Ir-S-C-S skeleton， have been successfully synthesized. These complexes use 4-（4-（trifluoromethyl）phenyl）quinazoline （4tfmpq） as the main ligand and dithiocarbamate derivatives （Na-Pydtc and Na-Indtc） as the ancillary ligands. The abundant nitrogen heterocycles in their molecular structure enhance the electron mobility， while the different electron-donating units in the dithiocarbamate derivatives help to regulate photophysical properties. The complex （4tfmpq）2Ir（Pydtc） exhibited an emission peak at 611 nm and the quantum yield of 92.7%. The emission peak and quantum yield of complex （4tfmpq）2Ir（Indtc） were 614 nm and 90.9%， respectively. High-performance organic light-emitting diodes （OLEDs） using the double emissive layer structure were prepared by employing these two complexes as dopant. For device D1 using （4tfmpq）2Ir（Pydtc） as dopant， the maximum current efficiency （ηc，max） and maximum external quantum efficiency （EQEmax） reached 56.29 cd·A-1 and 32.53%， respectively， and the CIE （Commission Internationale de l´Eclairage） coordinates were （0.61， 0.37）. In addition， the device showed a lower efficiency roll-off at the brightness of 1000 cd·m-2， with the EQE remaining at 28.44%. These results demonstrate the potential application of iridium （III） complexes containing a four-membered ring Ir-S-C-S skeleton in OLEDs.关键词：electroluminescence;organic light-emitting diode;iridium complex;red emission;dithiocarbamate
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更新时间：2024-07-15 - “在荧光探针研究领域，科研团队成功制备了新型配体ARC，并与Fe3+络合生成荧光探针ARC-Fe3+。该探针可高选择、高灵敏地识别焦磷酸根离子，检测限低至1.12×10^-8 mol/L，并已应用于细胞和活鼠体内的荧光成像研究。”摘要：A novel ligand ARC was synthesized by condensation reaction of naphthalene ［2，1-b］ furan-2-carbohydrazide and 4-formyl-3-hydroxy-N-butyl-1， 8-naphthalenediimide. The ligand ARC was synthesized by 1∶1 complex reaction with Fe3+. It was studied by high-resolution mass spectroscopy （HR-MS）， NMR hydrogen spectroscopy （1H NMR）， UV spectroscopy， and fluorescence spectroscopy. The results showed that the probe ARC-Fe3+ can identify pyrophosphate with high selectivity and sensitivity through fluorescence "OFF-ON". The detection limit of the probe ARC-Fe3+ to identify pyrophosphate is 1.12×10-8 mol/L， and the response to pyrophosphate can be completed within 60s. The probe ARC-Fe3+ has been successfully applied to the fluorescence imaging of pyrophosphate in cells and living mice， so it can be applied to various fields such as food， medicine， medical treatment and environment in the future.关键词：Fe3+ complex;fluorescent probe;PPi;cell imaging;Live mouse imaging
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更新时间：2024-07-15 - “最新研究进展显示，硫量子点作为新型纳米发光材料，在光学传感器领域具有广泛应用前景。专家深入探讨了其合成方法及在环境污染物和生物小分子检测中的应用，为未来纳米技术发展提供了新思路。”摘要：With the rapid development of nanotechnology， various types of sulfur nanomaterials have been developed， including sulfur nanoparticles， sulfur quantum dots， and other sulfur-containing nanocomposites with hybrid structures. As a new type of "zero-dimensional" nano-luminescent material， sulfur quantum dots are attracting more and more attention from scholars due to their photoluminescence properties， low toxicity， and ease of preparation. First， this review explores the synthesis of sulfur quantum dots. Then， it introduces the progress and application of sulfur quantum dots as sensing materials in optical sensor technology， and discusses in depth their detection applications in environmental contaminants and biosmall molecules. Finally， it summarizes the current challenges faced by sulfur quantum dots and looks forward to their future development.关键词：sulfur quantum dots;optical sensing;Environmental contaminants;Biosmall molecules
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更新时间：2024-07-15 - “最新研究发现，一种新型荧光分子探针SPA能高效检测人体锌离子，为相关疾病预防和治疗提供重要工具。”摘要：Zinc ion （Zn2+）， as a vital trace metal element for the human body， playing a key role in maintaining the normal physiological function of the human body， energy conversion， metabolism and signal transmission， etc. The detection and monitoring of Zn2+ in the body was of great significance for the prevention and treatment of related diseases. A colorimetric responsive fluorescent probe （SPA） for Zn2+ was designed and synthesized by condensation of naphthalene and ［2，1-b］ furan-2-carbohydrazide with 4-（diethylamino） salicyl aldehyde. The fluorescence of probe SPA was greatly enhanced and the wavelength was obviously red-shifted after the identification of Zn2+. The response mechanism of probe SPA to Zn2+ was investigated by HR-MS. The detection limit of Zn2+ recognized by probe SPA can be as low as 1.13 nmol/L. The probe SPA has been successfully applied to confocal imaging of Zn2+ in HeLa cells and fluorescence imaging of Zn2+ in live mice in vivo.关键词：Naphthofuran， Zinc， Fluorescent probe;Cellular imaging;Mice imaging
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更新时间：2024-07-13 -
Highly efficient narrow emission blue OLED devices based on dinaphtho[2,3-B:2',3'-D]furan moiety 增强出版 AI导读
“在柔性显示领域，研究人员设计合成了一种新型D-A-D型蓝光分子DPF-NA，具有高发光效率和高激子利用率，为高效率窄光谱蓝色有机电致发光器件（OLED）的发展提供了新思路。”摘要：High-efficiency narrow-emission blue organic light-emitting device （OLED） is one of the research hotspots in the field of flexible display. In this paper， a D-A-D blue molecule， DPF-NA was designed and synthesized by using dinaphthyl［2，3-B：2'，3'-D］furan as a weak electron acceptor and N-（4-biphenylyl）-1-naphthylamine as electron donors. The molecule shows a photoluminescence （PL） peak at 441 nm in n-hexane solution. Theoretical calculations and photophysical measurements show that DPF-NA possesses hybridized localized charge transfer （HLCT） excited state characteristics， combining high luminescence efficiency of the localized state （LE） and high exciton utilization of the charge transfer （CT） state. As a consequence， the molecule shows a high PL photoluminescence quantum efficiency （PLQY） of 81.2% in dichloromethane solution. OLED devices based on the DPF-NA film （with a doping concentration of 3 wt%） has an electroluminescence （EL） peak located at 455 nm， with a small full width at half maximum （FWHM） of 26 nm.. The CIE coordinates are （0.14， 0.08）， and the maximum external quantum efficiency （EQEmax） is 6.76%.关键词：OLED;dinaphtho［2，3-B：2'，3'-D］furan;Blue emission;exciton utilization;external quantum efficiency- 70
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更新时间：2024-07-01 - 摘要：A novel self-recoverable mechanoluminescent phosphor Ca5Ga6O14：Eu3+ was developed by the high-temperature solid-state reaction method， and its luminescence properties were investigated. Ca5Ga6O14：Eu3+ can produce red mechanoluminescence； importantly， it shows good repeatability. The mechanoluminescence of Ca5Ga6O14：Eu3+ results from the piezoelectric field generated inside the material under stress， rather than the charge carriers stored in the traps， which can be confirmed by the multiple cycles of mechanoluminescence tests and heat treatment tests. The mechanoluminescence color can be turned from red to green by co-doping varied concentrations of Tb3+， which may be meaningful for encrypted letter writing. The encryption scheme for secure communication was devised by harnessing mechanoluminescence patterns in diverse shapes and ASCII codes， which shows good encryption performance. The results suggest that the mechanoluminescence phosphor Ca5Ga6O14：Eu3+， Tb3+ may be applied to the optical information encryption.关键词：Phosphor;mechanoluminescence;self-recoverable;information encryption
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更新时间：2024-07-01 -
Ionic Liquid-Doped Organic Polymer Memristors for Low-Voltage Artificial Optoelectronic Synapses 增强出版 AI导读
“最新研究突破冯诺依曼瓶颈，利用掺杂离子液体的有机聚合物忆阻器实现节能神经形态计算，为低功耗高性能有机神经形态设备设计提供重要指导。”摘要：Memristor-based neuromorphic computing showcases great potential for overcoming the von Neumann bottleneck and enabling energy-efficient data processing. Organic polymers， due to their excellent semiconductor and optoelectronic properties as well as solution processability， are ideal candidates for low-cost memristor and synaptic applications. However， the high operating voltage and random switching of resistive states in polymer memristors limit their performance in neuromorphic chips and increase the complexity of peripheral circuits. In this study， the polymer MEH-PPV doped with ionic liquid ［EMIM］［PF6］ was used as the active layer to construct a vertically structured memristor. This design provides a variety of short-term and long-term synaptic plasticity behaviors， which can be modulated by electrical and optical inputs， achieving a significant reduction in operating voltage and an expanded range of tunable conductance states. The memristor exhibited key features of optically modulated biological synapse and brain-inspired learning and memory characteristics at mV-level voltage while integrating photodetection， memory， and processing functions into a single compact device. Additionally， this organic synaptic array was applied to image recognition and memory tasks in the human visual neural system. The promising results provide important insights for the design of next-generation low-power and high-performance organic neuromorphic devices.关键词：memristor;organic polymer;ionic liquid;optoelectronic synapse;image recognition- 40
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更新时间：2024-07-01 - “最新研究发现，以天然菠菜为碳源制备的多色发光碳点在生物成像、传感等领域具有广泛应用前景。通过不同反应溶剂，成功制备了6种单波长激发的生物质碳点，可发射覆盖整个可见光区的荧光。研究揭示了荧光机理，为多色碳点的应用发展提供了新途径。”摘要：Multicolor emission carbon dots（CDs） have widespread application prospects in bioimaging， sensing， light-emitting diodes and catalysis. However， to date， it remains a long-standing challenge to prepare tunable-emission multicolor CDs using biomass materials as carbon sources. Herein， six types of biomass carbon dots （BCDs） with adjustable emission from 450 nm to 680 nm under a single wavelength excitation were successfully prepared using nature spinach as carbon sources via changing reaction solvents. The obtained BCDs were characterized by morphology， size， element composition and optical properties. Among all the BCDs， the average diameters of blue， yellow， pink and red BCDs were 2.25 nm， 4.15 nm， 1.73 nm and 7.96 nm， respectively.These BCDs had high quantum yields （ 12.68-30.77%） . The fluorescence mechanism of the tunable BCDs was mainly attributed to the interaction between the carbon core’s conjugation degree and surface groups， which was analyzed by investigating the structure， composition and optical properties of CDs. Moreover， chiral films with iridescence were prepared by evaporation-induced self-assembly via dispersing blue， yellow and red BCDs into CNC solution， respectively， followed by characterizing their optical performance. This research pave the way to a new development in view of application for multicolor BCDs.关键词：carbon dots;Multicolor emission;multi-emission peaks;cellulose nanocrystals;circularly polarized luminescence
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更新时间：2024-06-17 - “最新研究突破：科学家们开发出一种新型自驱动光电探测器，采用硼酸表面处理和退火工艺，显著提升了氧化锌量子点材料的光电性能，响应速度达到0.93毫秒，为紫外光电探测器性能优化提供了新方案。”摘要：Zinc oxide nanomaterials （ZnO） hold tremendous potential in the field of self-powered photodetection due to their unique physical and chemical properties. However， self-powered photodetectors based on ZnO nanomaterials currently face challenges such as complex structures， slow response speed， low responsivity and detectivity etc.， making it difficult to meet practical application requirements. In this study， simple structured ITO/ZnO quantum dots （QDs）/Au photodetectors with fast response speed were fabricated. A surface treatment process combining Boric acid （BA） surface treatment with annealing was carried out， which successfully reduced the surface state density in ZnO quantum dot films and increased the device's detectivity by approximately an order of magnitude. The rise and fall times of the device at 0 V were 1.29 ms and 1.31 ms， respectively， achieving an on/off ratio of 10⁴ and a responsivity as high as 8.81 mA/W. Applying this process to bandgap-tunable Mg²⁺-doped quantum dot-based photodetectors similarly improved the detectivity and responsivity of the devices. A high-response-speed self-powered photodetector with a rise time of 0.93 ms was obtained， and as the Mg doping concentration increased， the rise time of the device decreased. This work demonstrates that the combined BA surface treatment with annealing process significantly enhances the performance of chemically synthesized ZnO materials， with potential widespread application in performance optimization of photodetectors based on ZnO nanomaterials.关键词：zinc oxide quantum dots;Self-powered photodetector;Solution surface treatment;Bandgap tuning
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更新时间：2024-06-15 -
Synthesis and Luminescence Properties of Abnormal Thermal Quenching Red Phosphor Sr2Ga2SiO7:Sm3+ 增强出版 AI导读
“最新研究揭示，采用高温固相法合成的Sr2-xGa2SiO7：xSm3+红色荧光粉，具有高热稳定性和量子效率，为WLED发光材料领域提供新解决方案。”摘要：Using the high-temperature solid-phase method， a series of Sr2-xGa2SiO7： xSm3+ red phosphors were synthesized. The synthesized phosphors were characterized by X-ray diffraction （XRD）， scanning electron microscopy （SEM）， photoluminescence （PL） spectra， high-temperature luminescence spectra， fluorescence quantum efficiency， and fluorescence decay lifetime to investigate their phase composition， crystal structure， luminescent properties， and thermal stability. The results indicate that under 404 nm UV excitation， the Sr2-xGa2SiO7： xSm3+ phosphors emit bright red light at 598 nm. The luminescence intensity of Sr2-xGa2SiO7： xSm3+ phosphors varies with the concentration of Sm3+ ions， exhibiting concentration quenching at x = 0.03 due to dipole-dipole interactions. As the temperature increases， the phosphors display anomalous thermal quenching behavior， reaching maximum luminescence intensity at 393 K， which is 102.5% of that at room temperature. At 473 K， the luminescence intensity can still maintain 101.3% of that at room temperature. Additionally， the fluorescence quantum efficiency of the optimal sample can reach 72.5%. The research demonstrates that Sr2-xGa2SiO7： xSm3+ red phosphors are promising luminescent materials for white light-emitting diodes （WLEDs） due to their high thermal stability and quantum efficiency.关键词：abnormal thermal quenching;high-temperature solid-state method;silicate;Sm3+ doped- 78
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更新时间：2024-06-15 - “最新研究揭示了六方氮化硼中单光子源的物理特性和制备技术，为光量子科技的进步提供了新方向。”摘要：Quantum emitter， the cornerstone of quantum information science and technology， are essential for advancing light quantum science and technology. The realization of efficient， stable and easily accessible single photon sources is the key to promote the development of related technologies. Currently， single-photon sources in hexagonal boron nitride （h-BN） have attracted much attention due to their high brightness and excellent room-temperature optical stability. This paper outlines the current research status and physical properties of single-photon sources in h-BN， details various preparation techniques for realizing precisely localized single-photon sources in h-BN； and explores the application of single-photon sources based on h-BN in different applications， such as coupling with optical microcavities and waveguides， and their modulation by external electric fields or stresses. Finally， the paper summarizes the opportunities and challenges facing single photon sources in hexagonal boron nitride and discusses the research directions currently being explored as well as new possibilities for the future.关键词：two-dimensional materials;hexagonal boron nitride;solid-state single photon source;quantum photonics
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更新时间：2024-06-13 - “荧光碳点在发光领域取得显著进展，本文总结了其在电致发光器件的最新研究，为实现高性能器件提供策略和展望。”摘要：Fluorescent carbon dots （CDs） have excellent characteristics such as wide range of raw materials， non-toxic and non-polluting， adjustable luminescence color， low cost and biocompatibility， and have broad application prospects in the field of luminescence. In recent years， CDs-based electro-luminescent devices have a great achievements. In this paper， we mainly summarize the latest progress of CDs-based electroluminescent devices， even focus on the feasibility of synthesizing high-efficiency CDs and manipulating the device structure to obtain high-performance devices. In addition， combined with the analysis of the development status and future needs of CDs in the application of electroluminescent devices， this paper looks forward to the realization of high-performance CDs-based electroluminescent devices.关键词：carbon dots;Electroluminescent;LED;performance;All Solution.
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更新时间：2024-06-12 - “最新研究进展：通过水热法和真空热处理制备出具有反尖晶石结构的ZnxMg0.993-xGa2O4：0.7％Ni2+近红外二区荧光粉，成功应用于夜视成像和生物组织成像。”摘要：Herein， a series of ZnxMg0.993-xGa2O4：0.7%Ni2+（x=0-0.5）（ZMGO：Ni2+）phosphors with inverse spinel structure were successfully prepared through a hydrothermal method followed by a vacuum heat treatment， emitting within the 2nd near-infrared transmittance window（NIR-II： 1000-1700 nm）. The particle size of ZMGO：Ni2+ phosphors exhibited a gradual increase with increasing Zn2+doping content. Upon excitation by a 635 nm laser， ZMGO：Ni2+ phosphors exhibited a broad emission band centered at approximately 1279 nm， which can be attributed to the characteristic emission of Ni2+. Their thermal activation energy is increased from 224 to 242 meV with increasing Zn2+ doping concentration. A NIR-II phosphor-converted light-emitting diode （NIR-II pc-LED） was fabricated by employing ZMGO：Ni2+ phosphors with the strongest luminescence intensity， in conjunction with a 620 nm red LED chip. Based on high penetration ability， minimal scattering property and auto-fluorescence-free background of NIR-II light， night vision imaging with occlusion and tissue imaging were performed using the NIR-II pc-LED， respectively.关键词：photoluminescence;transition metal ion;NIR-II;phosphors
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更新时间：2024-06-12 - “在激光医疗和食品药品检测领域，研究人员开发了高功率1150 nm垂直外腔面发射半导体激光器（VECSEL），通过大尺寸基模光斑外腔结构和增益峰-腔模失谐结构，实现了9.38 W的高功率激光输出和稳定的激光波长控制。”摘要：Aiming at the application requirements of orange-yellow laser in the fields of laser medicine， food and drug detection， we have carried out research on high-power fundamental frequency 1150 nm vertical external cavity surface emitting semiconductor laser （ VECSEL ）. In this paper， a large-size fundamental mode spot external cavity structure in the laser resonant cavity is proposed to make the VECSEL cavity mode match the larger pump spot size to achieve high-power laser output. The gain peak-cavity mode detuning structure is proposed. The gain peak is different from the temperature drift coefficient of the cavity mode. The gain peak-cavity mode matching is good at high pump power， and the laser wavelength stability control under high pump power is realized. The output power of the VECSEL device prepared by us reaches 9.38 W at the laser wavelength of 1150 nm， and a good circular symmetrical output spot morphology is obtained. The divergence angles of the spot in the orthogonal direction are 7.3 ° and 7.5 °， respectively.关键词：semiconductor laser;VECSEL;gain chip;strained quantum well
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更新时间：2024-06-12 -
High sensitivity submicron scale temperature sensor based on perovskite nanoplatelet lasers 增强出版 AI导读
“Researchers have developed a submicron-scale temperature sensor with exceptional sensitivity, utilizing a triangular MAPbI3 nanoplatelet laser. The sensor's peak wavelength shifts linearly with temperature changes, enabling precise measurements. This advancement offers a new direction for the development of ultrasmall temperature sensors, suitable for compact systems.”摘要：Submicron scale temperature sensors are crucial for a range of applications， particularly in micro and nanoscale environments. One promising solution involves the use of active whispering gallery mode （WGM） microresonators. These resonators can be remotely excited and read out using free-space structures， simplifying the process of sensing. In this study， we present a submicron-scale temperature sensor with a remarkable sensitivity up to 185 pm/℃ based on a triangular MAPbI3 nanoplatelet （NPL） laser. Notably， as temperature changes， the peak wavelength of the laser line shifts linearly. This unique characteristic allows for precise temperature sensing by tracking the peak wavelength of the NPL laser. The optical modes are confined within the perovskite NPL， which measures just 85 nanometers in height， due to total internal reflection. Our NPL laser boasts several key features， including a high Q of ~ 2610 and a low laser threshold of about 19.8 µJ cm-2. The combination of exceptional sensitivity and ultra-small size makes our WGM device an ideal candidate for integration into systems that demand compact temperature sensors. This advancement paves the way for significant progress in the development of ultrasmall temperature sensors， opening new possibilities across various fields.关键词：Temperature sensor;submicron scale;perovskite nanoplatelet- 53
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更新时间：2024-06-11 - “最新研究揭示了垂直腔面发射激光器（VCSEL）的热管理技术，通过有限元计算模型分析不同封装方式对VCSEL热特性的影响，为有效散热封装提供了优化方案。”摘要：Vertical-cavity surface-emitting lasers （VCSELs） is easily integrated on-chip and is a key optoelectronic device in systems such as laser radar and security lighting. However， the severe self-heating phenomenon can affect the output power， high-speed characteristics， and stability of the devices. Therefore， thermal management technology is extremely important， and adopting an optimized packaging approach can effectively increase the heat dissipation of VCSELs， which is an important method to improve VCSELs' thermal performance. This article is based on a finite element method （FEM） computational model to numerically analyze the thermal characteristics of VCSELs with different packaging methods and a thin copper layer covering the devices' surface.The simulation results indicate that compared to the top-emitting packaging method， the flip-chip packaging with substrate-emitting （fully etched top and bottom DBR） can effectively reduce the active region temperature， with a reduction rate exceeding 56%. As the device mesa diameter gradually increases， devices using the top-emitting packaging method show a decreasing trend in temperature and thermal resistance， with a temperature reduction 50℃ and the thermal resistance reduction of over 3.25 K/mW. However， devices with a fully etched top and bottom DBR structure using flip-chip packaging and devices with only etched P-DBR structure using flip-chip packaging both exhibit an slowly increasing trend in temperature and thermal resistance， with temperature increases of 2℃ and thermal resistance increases of 0.15 K/mW. Covering the device mesa， sidewalls， and substrate surfaces with a layer of copper can effectively reduce the temperature of the active region. When the thickness of the copper layer is 3 μm， the temperature reduction of the active region is 43% and thermal resisitance reduction is 1.9 K/mW. This article analyzes the impact of packaging methods on the thermal characteristics of VCSELs and proposes optimization solutions， which have guiding significance for the effective thermal packaging of VCSELs.关键词：VCSEL;thermal characteristics;temperature;thermal resistance
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更新时间：2024-06-06 -
Preparation of new single component solid carbon dots for white LED with high color rendering index 增强出版 AI导读
“在LED照明领域，一项突破性研究成功开发出新型荧光碳点，有效克服了聚集诱导荧光猝灭效应，为高显色指数白光LED器件提供了理想的单组分荧光粉，固态量子产率高达37%，显著提升了光电性能。”摘要：In recent years， the demand for white LED lighting with high color rendering index has posed new challenges to the LED industry. Carbon dots， as a new type of nanomaterial in the 21st century， is expected to become an ideal single component phosphor for white LED devices with high color rendering index， because of its advantages of simple preparation process， high stability， optical tunability and wide emission. However， aggregation-caused quenching （ACQ） of carbon dots greatly limits its application in solid-state lighting. In this paper， a high-efficiency fluorescent carbon dots were synthesized by microwave method under mild preparation process with phenphenolline as raw material， and the surface functional group tuning of the carbon dots was realized by doping technique. A one-component solid carbon dots phosphors with anti-ACQ were successfully prepared by one-step method， which can be applied to white LED devices with high color rendering index. Its solid quantum yield is as high as 37%， and the white LED prepared with it as phosphor shows excellent photoelectric performance.关键词：Solid state luminescence;carbon dots;LED- 90
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更新时间：2024-06-06 - “最新研究显示，石墨烯/WS2复合材料在中红外波段锁模激光器中表现出优异的非线性吸收特性，成功实现低阈值、高损伤阈值的锁模脉冲运转，为中红外激光技术发展提供新思路。”摘要：Graphene and transition metal sulfide WS2 have stable chemical properties and broadband absorption spectra， which can realize the pulse operation of laser in the mid-infrared band. This paper reports the application of graphene and WS2 as saturable absorbers in mode-locked lasers in mid-infrared band. Experiments show that graphene/WS2 composites have better nonlinear absorption characteristics， and exhibit low mode-locked threshold and high material damage threshold during mode-locked modulation. When the pump power is 5 W， The mode-locked pulse with pulse width of 24.04 ps was obtained at 2781.7 nm. The maximum average output power of the laser was 237.7 mW and the peak power was 395.5 W. Finally，Finally， the wavelength tunable output of the laser is realized by grating， and the output wavelength of the graphene/WS2 mode-locked laser is widened to 2730-2810 nm.关键词：mid-infrared laser;mode locking;the wavelength is tunable;graphene;WS2
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更新时间：2024-06-04
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